There are proposed various kinds of apparatuses for photographing a golfer's swing, automatically computing information such as a flight distance (distance from hitting point to drop point), trajectory, and the like of a hit golf ball by a computer, and displaying obtained information for a golfer. These apparatuses allow the golfer to examine the flight distance, trajectory, and the like of the hit ball. However, these apparatuses are incapable of providing information useful for improving the golfer's swing form.
In the swing form-diagnosing apparatus disclosed in Japanese Patent Application Laid-Open No. 2003-117045, a golfer's swing form is photographed to extract images of only specific moving points important for diagnosing the swing form. More specifically, frames regarding the golfer's swing motion are extracted from the golfer's moving image photographed by the photographing means. Specific moving points during the swing motion are judged according to results of analysis of the moving partial images in the differential image obtained by executing differential processing between each frame and the reference image. The frame corresponding to each of the specific moving points is extracted to display the swing image The image at the impact time is regarded as important for diagnosing the swing form. Thus image extraction is executed by giving attention to the impact image.
However, even though the frame corresponding to the specific moving point during the swing motion is extracted, the golfer cannot be provided with the motion of the joints and the like during the swing by merely looking at the extracted image. Therefore it is difficult for the golfer to find defects in her/his swing form and points to be corrected.
In the motion-diagnosing apparatus disclosed in U.S. Pat. No. 2,794,018, to diagnose a person's swing form, a plurality of moving points are provided on a golf club head and on the person to obtain the coordinates of the moving points in a swing moving image. But it is necessary to perform computations for extracting the coordinates of a large number of moving points for all frames of the swing moving image. Therefore the amount of computation is very large, and an erroneous recognition of the coordinates of the positions of the moving points occurs at a high percentage. Further there is a case in which the moving points are hidden with the golfer's arm and the like while the golfer is swinging. In this case, a camera is incapable of recognizing the moving points. Consequently it is impossible to obtain the coordinates of the positions of the moving points. Thus there is a high probability that the swing form is erroneously diagnosed. Another problem of this motion-diagnosing apparatus is that although numerical data such as the angle of the arm and the angle of the golf club is computed from coordinate data obtained by pursuing the moving points P1 to P6, how to utilize the obtained numerical data is not apparent. Such being the case, there is a growing demand for the development of systems capable of diagnosing the swing form and giving golfers advice.
Because the above-described apparatuses are installed at golf shops or the like, users cannot check their swing form for a long time. As such, these apparatuses are not convenient for the users.
Patent document 1: Japanese Patent Application Laid-Open No. 2003-117045
Patent document 2: U.S. Pat. No. 2,794,018